Purification and properties of a phytate-degrading enzyme produced by Enterobacter sakazakii ASUIA279.
An extracellular phytate-degrading enzyme produced by Enterobacter sakazakii ASUIA279 was purified to homogeneity using FPLC anion exchange chromatography and gel filtration. The enzyme was purified about 66-fold with a recovery of 27%. Its molecular mass was estimated to be 43 kDa by SDS-PAGE. The...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English English |
| Published: |
Federal University of Tocantins
2012
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| Online Access: | http://psasir.upm.edu.my/id/eprint/24200/ http://psasir.upm.edu.my/id/eprint/24200/1/Purification%20and%20properties%20of%20a%20phytate.pdf |
| Summary: | An extracellular phytate-degrading enzyme produced by Enterobacter sakazakii ASUIA279 was purified to homogeneity using FPLC anion exchange chromatography and gel filtration. The enzyme was purified about 66-fold with a recovery of 27%. Its molecular mass was estimated to be 43 kDa by SDS-PAGE. The Michaelis constant (KM) and turnover number (kcat ) for sodium phytate at pH 5.0 and 50°C were calculated from the Lineweaver-Burk plot to be 760 µM and 4.14s-1, respectively. The enzyme showed narrow substrate specificity and not phytate, but GTP was dephosphorylated with the highest relative rate of hydrolysis. However, according to the kcat/KM values, phytate was concluded to be the in vivo substrate of the enzyme. Optimal activity was determined at pH 4.5 and 45-55°C. The enzyme was strongly inhibited by Fe3+, Cu2+, Zn2+, molybdate, vanadate, fluoride and phosphate (1 mM). |
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